McDonnell & Miller 157S-R Controller R-22 Durable Construction: Engineered to withstand

Durable Construction: Engineered to withstand the rigors of industrial mechanical rooms and frequent cycling

This unit features a power-open/power-close mechanism driven by a 24V motor

tailored for specific vertical coil configurations

5-ton systems

ensuring the airtight seal necessary to maintain precise inches of water column (WC) for the draft inducer

McDonnell & Miller 157S-R Controller R-22 Durable Construction: Engineered to withstandThe McDonnell & Miller 157S R (Part Number 176220) is a heavy duty, float operated combination low water cut off and pump controller designed specifically for steam boilers with an integral water column. This model serves as the upgraded direct replacement for the McDonnell & Miller 157 R, transitioning from older mercury switch technology to reliable, bimetal snap acting switches for enhanced safety and modern compliance. Built with a corrosion